Sensors have been used to dynamically monitor the charging/discharging current and working state of a vehicle battery, and feed back an acquired signal to a battery management system. The battery management system manages and controls the battery appropriately and effectively in conjunction with other acquired performance parameter(s), so as to ensure desirable battery performance and normal operation of electrical equipments.
According to design of an existing sensor (for example, a Hall sensor), a zero-drift phenomenon occurs at extreme high and low temperatures (especially at subzero temperatures): e.g., when a magnetic field is zero, an abnormal sensing signal is sent by the sensor, which makes the vehicle battery management system cannot work effectively.
FIG. 1 shows zero-drift curves of a sensor that vary with temperature in two drive modes: a current drive mode and a voltage drive mode, wherein the abscissa represents the ambient temperature T (° C.) of the sensor, and the ordinate represents the drift voltage output by the sensor. The dotted line 101 represents the drift curve in the current drive mode, and the solid line 102 represents the drift curve in the voltage drive mode. As can be seen from FIG. 1, when the ambient temperature is lower than 50° C., the output drift of the sensor in the current drive mode is greater than that of the sensor in the voltage drive mode; especially when the ambient temperature is below −40° C., the drift voltage in the current drive mode is 25 mV greater than that in the voltage drive mode; and when the ambient temperature is higher than 50° C., the output drift of the sensor in the current drive mode is smaller than that of the sensor in the voltage drive mode.